The present disclosure relates to a test fixture. More particularly, the present disclosure relates to a test fixture for testing an electrochemical cell, and to a method for using the same.
Large-scale electrochemical batteries are often used in the military industry, such as to power missile systems and submarines, and in the aerospace industry, such as to power space shuttles and astronaut assistance equipment. Such large-scale batteries may contain numerous electrochemical cells and may be shielded by an outer case. For example, battery 100 shown in FIG. 1 contains over forty individual electrochemical cells 102 and is shielded by an outer aluminum case 101.
One cell 102 from battery 100 is shown in FIG. 2. Each individual cell 102 behaves like a distinct battery, having its own negative electrode (anode) 114 coupled to a negative terminal 104 and positive electrode (cathode) 116 coupled to a positive terminal 106. An exemplary cell may contain a plurality of negative plates as the anode 114 and a plurality of positive plates as the cathode 116.
The battery may be in the form of a silver-zinc battery, each individual cell having its own negative zinc electrode (anode) and positive silver oxide electrode (cathode). In use, the electrodes may be exposed to an electrolytic solution, such as sodium hydroxide (NaOH) or potassium hydroxide (KOH), so that the zinc at the anode is oxidized and the silver at the cathode is reduced.
Before a certain batch of batteries can be used in the field, an individual battery from the batch, such as battery 100 of FIG. 1, may be tested. Testing battery 100 may involve removing and testing individual cells of battery 100, such as cell 102 of FIG. 2. In the past, a tester would have to pot each cell in a liquid resin that, when hardened, formed a protective coating capable of containing the cell's corrosive, electrolytic solution. However, this potting process presented several disadvantages. First, the potting process was time consuming and expensive. In fact, two days were generally required to pot and test one individual cell. For a large, multi-cell battery, which may contain up to forty individual cells or more, the entire testing process could take up to six months. Also, the potting process could expose the tester to hazardous potting resins. Additionally, the potting resin released heat while curing, which artificially aged the cell being tested.
According to an illustrative embodiment of the present disclosure, a container is provided for testing an electrochemical cell having at least one anode and at least one cathode. The container includes a base and a lid movably coupled to the base between an open position and a closed position, the base and the lid cooperating to define an internal cavity that is sized to receive the electrochemical cell. With the lid in the closed position, the container includes a first opening into the internal cavity that is sized to receive a first wire in electrical communication with the at least one anode of the electrochemical cell, a second opening into the internal cavity that is sized to receive a second wire in electrical communication with the at least one cathode of the electrochemical cell, and a third opening into the internal cavity that is configured to direct an electrolytic solution into the internal cavity.
According to another illustrative embodiment of the present disclosure, the container is part of a system for testing a multi-cell battery having a first electrochemical cell and a second electrochemical cell. The internal cavity of the container is sized to interchangeably receive the first and second electrochemical cells.
According to yet another illustrative embodiment of the present disclosure, a method is provided for testing an electrochemical cell, the electrochemical cell having at least one anode and at least one cathode, the electrochemical cell including a first wire coupled to the at least one anode and a second wire coupled to the at least one cathode. The method includes the steps of: providing a container including a base and a lid, the base and the lid cooperating to define an internal cavity; placing the electrochemical cell within the internal cavity of the container with the first wire extending out of the container through a first opening in the container and the second wire extending out of the container through a second opening in the container; coupling the first and second wires to a test apparatus; closing the lid of the container; injecting an electrolytic solution into the internal cavity of the container through a third opening in the container; and using the test apparatus to test the electrochemical cell.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.